Planning the Best Pipeline Route

The preferred water pipeline route continues to evolve through a comprehensive process that includes gathering additional information from in-depth design, engineering and environmental studies, discussions with property owners, and input from local partner jurisdictions.

Recently, Water Supply staff worked with engineering consultants to complete a feasibility study on a section of pipeline along Cornelius Pass Road. The preliminary design identified constructability challenges along parts of Cornelius Pass Road and suggested a “bump out” from Cornelius Pass Road to 205th /206th Avenues in Hillsboro (between Baseline and Amberwood Road). However, when Water Supply engineers investigated the possibility further they determined the Cornelius Pass Road alignment is constructible and the “bump out” would not be necessary, which will decrease the route length and the number of stream crossings. The revised route will also save construction time and project cost. Through careful evaluation of the proposed routing we are creating a more efficient, cost effective, and less intrusive project while building a water delivery system capable of serving our region for generations to come.

Route before change

Route after change

Program Update Highlights

South Hillsboro Area Pipeline Project – Water Supply staff are working closely with partners to plan, design, and build the pipeline through the Cornelius Pass Road and TV Highway intersection. This inter-agency cooperation promotes coordination on future expansion of Cornelius Pass Road to the north and the future southern extension into South Hillsboro. Visit the project website for more information.

Community Outreach — Water Supply staff continue to contact hundreds of property owners along the proposed pipeline route to secure permission to enter their properties for survey work. This access, when granted, will allow Water Supply staff to complete wetland, cultural, geotechnical, and other environmental studies on properties that may be needed for construction staging or placement of infrastructure when construction begins. Additional surveys will be conducted this fall along the pipeline route. Geotechnical drilling is also underway along some sections of the route, and land surveyors are documenting topographical features along the approximately 30-mile route.

124th Avenue Partnership Project — Work continues on this opportunity project with Washington County. Installation of the pipeline portion of the project is anticipated to begin this fall, with pipe delivery expected in September or October. The pipe for this section of the project was purchased from local pipe manufacturer Northwest Pipe. Visit the 124th Avenue website for more information.

Kinsman Road Partnership Project — Construction has begun on this cost-saving opportunity project with the City of Wilsonville and the Federal Highway Administration. Construction is anticipated to conclude in 2017. Visit the Kinsman Road project website for more information.